Service difficulty report · Rod End · Cvac 340CVAC

Difficulty date
January 28, 2013
Submitted
September 14, 2015
Operation
General aviation
Make and model
Cvac 340CVAC
Aircraft time
16,798 hours
Engine
Allsn 501D22
Propeller
Hamstd 54H60
Part
Rod End
Part number
DREMHD6T2
Condition
Worn
Location
Engine Mount
Part time
206 hours
Stage of operation
CR
How discovered
O
Nature of condition
E
Precautionary procedure
O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

(CAN) IN THE SUMMER OF 2011,PILOTS REPORTED THAT AT HIGH POWER SETTINGS IN CRUISE A HIGH FREQUENCY VIBRATION WAS FELT IN THE OTBD RUDDER PEDALS AND THE SEAT FRAMES. IT WAS ALSO NOTICED THAT THE OTBD STATIC WICKS OF THE LT ELEVATOR WOULD BE MISSING AFTER SOME FLIGHTS. MAINTENANCE PERSONNEL INVESTIGATED BY INSPECTING THE PROPS,FAIRINGS, AND PERFORMING A TAIL SHAKE FOR LOOSE ATTACH POINTS. NO FINDINGS. FURTHER INSPECTIONS INCLUDED GRABBING THE LT PROP AND SHAKING IT QUICKLY FORWARD AND AFT. THIS RESULTED IN A BANGING NOISE COMING FROM THE TOP AFT AREA OF THE ENGINE. FURTHER INVESTIGATION FOUND THAT AT THE REAR ENGINE MOUNT, THE ROD END 13 ON THE INBD END OF TUBE ASSY 15 WAS WORN ENOUGH, VERY MINIMAL TO ALLOW SIDE TO SIDE PLAY IN THE ENGINE MOUNT. THIS METAL TO METAL CONNECTION CREATED THE AIRFRAME VIBRATION. AFTER REPLACING THE ROD END, THE VIBRATION CEASED. IT WAS ALSO NOTED THAT THE LT ELEVATOR STOPPED LOSING STATIC WICKS. THIS FALL THE VIBRATION RE-APPEARED AFTER 206 HRS SINCE THE ROD ENDS WERE LAST REPLACED. THE ROD ENDS WERE FOUND WORN AGAIN, REPLACED, AND THE VIBRATIONS CEASED AGAIN. THE AMO HAS BEEN WORKING AND CONTINUES TO WORK WITH THE TYPE CERTIFICATE HOLDER SINCE THE ORIGINAL FINDING WAS FOUND IN 2011 THE ORIGINAL SDR REPORT IN 2011 WAS FAILED TO BE ENTERED IN THE SDR DATABASE. THE AMO HAS TAKEN STEPS TO PREVENT THIS FROM RE-OCCURING.